Dredging head with pivotally mounted mud shield

ABSTRACT

A dredging head with a pivotally mounted mud shield and cooperating intake assembly. A head located at the end of a dredge boom has digging and conveying screw augers attached to a rotating shaft to loosen material such as mud, silt, and weeds from the bottom of a body of water and convey it toward an intake assembly which includes a suction intake conduit, a rotor, a stationary anvil, and an arcuate bar assembly. The mud shield confines material near the augers so the material can be conveyed by the augers to the rotor, stationary anvil, and arcuate bar assembly which cooperate to cut and shred the dredged material as it is pulled into the suction intake conduit. The arcuate bar assembly reinforces both suction intake conduit and stationary anvil and provides support for the rotor to prevent shaft deformation if collision with an underwater obstruction flexes the shaft against the arcuate bar assembly.

llnite States Patent 1 armon DREDGHNG HEAD WITH PIVOTALLY MOUNTED MUDSHIELD [75] Inventor: James D. Harmon, Minneapolis,

Minn.

[73] Assignee: Inland Service Corporation,

Minneapolis, Minn.

[22]. Filed: Dec. 10, 1970 [2]] Appl. No; 96,705

[52] US. Cl. 37/66, 37/57 [51] lnt. Cl E021 3/92 [58] Field of Search37/55, 57, 66;

[56] References Cited UNITED STATES PATENTS 3,521,387 7/1970 Degelman37/66 3,512,280 5/1970 Di Perna 37/57 2,204,584 6/1940 Flower 37/55 X1,070,271 8/1913 Lybeck 37/55 3,171,220 3/1965 Schram 37/66 2,362,40211/1944 Reiter 171/85 X 2,686,996 8/1954 Reiter 171/85 June 12, 1973[57] ABSTRACT A dredging head with a pivotally mounted mud shield andcooperating intake assembly. A head located at the end of a dredge boomhas digging and conveying screw augers attached to a rotating shaft toloosen material such as mud, silt, and weeds from the bottom of a bodyof water and convey it toward an intake assembly which includes asuction intake conduit, a rotor, a stationary anvil, and an arcuate barassembly. The mud shield confines material near the augers so thematerial can be conveyed by the augers to the rotor, stationary anvil,and arcuate bar assembly which cooperate to cut and shred the dredgedmaterial as it is pulled into the suction intake conduit. The arcuatebar assembly reinforces both suction intake conduit and stationary anviland provides support for the rotor to prevent shaft deformation ifcollision with an underwater obstruction flexes the shaft against thearcuate bar assembly.

11 Claims, 5 Drawing Figures 18 i l" l K PAIENIEDJuu 1 ems SHEU 1 0F 2INVENTOR.

PAIENIEIJ JUN] 2 ma SHEET 2 Bf 2 DREDGING HEAD WITH PIVOTALLY MOUNTEDMUD SHIELD The purpose of the foregoing abstract is to enable the PatentOffice and the public generally, and especially the scientists,engineers, or practitioners in the art who are not familiar with patentor legal terms of phraseology, to determine quickly from a cursoryinspection the nature and essence of the technical disclosure of theapplication. The abstract is neither intended to define the invention oftheapplication, which is measured by claims, nor is it intended to belimiting as to the scope of the invention in any way.

BACKGROUND OF THE INVENTION My invention comprises an improvement of thedredging head disclosed in co-pending United States patent applicationSer. No. 814,232, filed April 4, 1969 by Norbert V. Degelman entitledDredging Machine, now U. S. Pat. No. 3,521,387. That applicationdisclosed a pumping dredge for removing material such as mud, silt,weeds, and the like from the bottom of bodies of water such as lakes,marshes, and rivers. The disclosed dredge moved forward or rearwardalong a fixed cable propelling a dredging head along the bottom of thebody of water. The head extended horizontally and transversely of a boompivotally mounted to the dredge and carried a rotating horizontal shafthaving a pair of screw augers for loosening material from the bottom.The screw augers were spaced from each other on the shaft and carried aplurality of cutting blades for loosening material form the bottom. Therotation of the augers conveyed loosened material to a suction intakeconduit between the augers. The loosened material was pumped into theconduit and away from the dredging area.

As the dredging head moved forwardly along the bottom, all the materialloosened by the augers was not conveyed to the intake conduit; theaugers rotated with lowermost edge of the augers moving forwardly andconsequently hurling some of the loosened material upward out of reachof the augers. Such material was not conveyed by the augers to theintake conduit and thus was not always removed from the bottom.

When the dredge moved rearwardly, an increased amount of loosenedmaterial escaped from the augers because the material could be hurledboth upwardly and forwardly away from the augers. The present inventionincludes a mud shield formed of a panel of sturdy material overlying theaugers to confine material near the augers, permitting more material tobe removed from the bottom.

Because the addition of a mud shield to the dredging head increases thequantity of loosened material confined near the augers for removal, itis helpful to modify the intake assembly of the dredging head to handlethe increased quantity of material.

SUMMARY OF THE INVENTION The invention comprises an improved dredginghead for a pumping dredge. A pivotally mounted mud shield formed of apanel of sturdy material overlies the rotating augers of the head andconfines loosened material near the augers. Means are provided to varythe position of the mud shield to adapt it to forward and rearwarddredging at various water depths.

An intake assembly at the center of the dredging head has a suctionintake conduit, a rotor, a stationary anvil, and an arcuate barassembly. The rotor is attached to the rotating shaft on which theaugers are mounted and is provided with a plurality of cutting blades.The rotor with its blades cooperates with the stationary anvil to cutmaterial such as weeds and mud clods therebetween. This diminishes theamount of oversize material which might otherwise clog the suctionintake conduit.

The arcuate bar assembly reinforces the intake conduit and divides it inhalf to prevent large rocks or clods from entering. The bar assembly isaligned with and confronts the rotor, and the rotor cutting bladescooperate with the bar assembly to cut and shred material and hurloversize rocks or clods from the intake conduit thereby furtherprotecting the conduit from obstruction. The bar assembly has an arcuatebar which provides support for the rotor so as to prevent shaftdeformation if collision with an underwater obstruction flexes the shaftagainst the arcuate bar assembly.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional side view of adredge embodying my improved dredging head showing the dredge movingrearwardly to clear the bottom of a body of water. The screw augers ofthe dredging head have been omitted from FIG. 1 for simplification.

FIG. 2 is a side view of the dredging head and lower boom of FIG. 1showing them operating in a forward direction.

FIG. 3 is a front elevational view of the dredging head of FIGS. l and 2showing my mud shield and improved intake assembly.

FIG. 4 is a sectional side view of the intake assembly of FIG. 3 takenalong cutting plane 44.

FIG. 5 is a sectional view of the rotor and arcuate bar assembly of myinvention taken along cutting plane 5-5 of FIG. 4.

DESCRIPTION AND OPERATION OF THE INVENTION FIG. 1 shows a dredge 10moving rearwardly as indicated by arrow 12 and clearing the bottom 14 ofa marsh or other body of water. The dredge 10 has a boom 16pivotally'mounted between dredge supporting pontoons 18, one of which isomitted for simplification, and carries a dredging head 20 at the lowerend of the boom.

A cable 22 extends through the dredge 10 with one end of the cableanchored on shore and the other at a distance out in the marsh. Winch 24powered by a reversible hydraulic motor 26 pulls the dredge forwardly orrearwardly along the cable 22 propelling the dredging head 20 over themarsh bottom to clear a swath. After clearing a swath the cables shoreanchorage point is moved to one side permitting the dredge to clear anadjoining swath.

A power source 28, such as a diesel engine, is mounted on the rear ofthe dredge and is connected through axle 30 to a dredge pump 32 whichdraws loosened material upward from the marsh bottom.

A suction intake conduit 34 begins at the center of the head 20 and isconnected to a flexible hose 36 leading to a rock collection box 38 inwhich rocks 40 pumped upward from the bottom are deposited. Dredgedmaterial is pumped through box 38 and into dredge pump 32 which has anoutlet 42 connected to a series of discharge hoses (not shown) whichdeliver the dredged material to a desired depository.

Boom 16 is raised or lowered by a hydraulic piston 44 to position thehead at the desired dredging depth. The head 20 has a pivotally mountedmud shield 46 which can be rotated about an axis substantially parallelto the head by hydraulic piston 48.

The hydraulic pistons 44 and 48 are powered by hydraulic pump 50 whichis connected by a belt drive to power source 28. The hydraulic pump 50also supplies power to all hydraulic motors of the dredge. Hydrauliclines between pump 50 and the motors or cylinders have been omitted forsimplification.

Referring now to FIGS. 3 and 4, the dredging head 20 has a frame 52attached to boom 16 and carrying rotatable shaft 54 which is turned byhydraulic motor 56.

The rotatable shaft 54 has a pair of spaced digging and conveying screwaugers 58 and 60 mounted thereon and extending horizontally andtransversely of the forward direction.

The hydraulic motor 56 turns augers 58 and 60, rotating the lowermostedges 61 of the augers forwardly as shown by arrow 63 in FIGS. 1 and 2.The direction of rotation 63 is the same for forward or rearwardoperation of the dredge 10. The augers have a plurality of cuttingblades such as 70, 71 and 72 which cooperate with toothed cutter bars 74and 76 to cut weeds, mud clods, and other loosened materialtherebetween.

Referring now to FIGS. 3 and 4, a moveable mud shield 46 formed of apanel 78 of sturdy material, such as sheet steel, is pivotally mountedto the frame 52 adjacent toothed cutter bars 74 and 76 for rotationabout an axis substantially parallel to the head so as to be moveablebetween a plurality of positions over-lying the augers. The panel 78 mayhave an arcuate cross section to provide additional strength; aplurality of ribs 80 provide additional strength and rigidity to thepanel. A bracket 82 on the panel 78 attaches to hydraulic piston 48(FIG. 1) which serves as a means to vary the angular position of thepanel about the axis. The hydraulic piston 48 is pivotally mountedbetween boom 16 and bracket 82.

Since the depth below the water surface at which the dredging head isused varies, the angle between boom 16 and march bottom 14 may varyconsiderably; for deeper bottoms the angle is greater than for shallowbottoms. As a result of this variation the mud shield position should beadjusted to the operating depth.

When the dredge is operated in a rearward direction 12 as shown in FIG.1 the mud shield 46 is preferably lowered to a position like that shownwhich confines much loosened material between the mud shield, toothedcutter bars, augers, and marsh bottom. The mud shield, toothed cutterbars, and augers cooperate to confine the loosened material between themand the marsh bottom so the suction intake conduit can remove theconfined material. When the dredge is operated in a forward direction 84as shown in FIG. 2, the mud shield occupies a different position,overlying the augers and the bank. The augers can be positioned toremove either relatively thick or thin layers of material from thebottom; the layer thickness affects the mud shield position. Forexample, when removing a relatively thick layer of material the augersconfront a bank 86 (FIG. 2) and the shield should overlie but not diginto the bank. If the bank 86 were less high, the shield 46 would belowered to be nearer the top of the bank thereby increasing theconfinement of loosened material.

When the dredge is being transported by truck or stored, the mud shieldis kept in the raised position illustrated by FIG. 3 to facilitatestorage by shortening the overall length of the dredge.

An intake assembly 62 (FIG. 4) is located at the center of the head 20and includes a rotor 64 on shaft 54, a stationary anvil 66, the suctionintake conduit 34, and a stationary arcuate bar assembly 68.

Rotor 64 on shaft 54 is mounted between the augers 58 and 60 and carriesfour cutting blades 88, 89, 90, and 91 with a pair of the blades beingmounted on each side of the rotor. The rotor 64 may be disk shaped withflat sides 92 and 94 separated by a circular rim, cutting blades beingcarried on the flat sides.

A stationary anvil 66 (FIGS. 3, 4) formed of rigid material such assteel, is attached to frame 52 and cooperates with rotor 64 and thecutting blades thereon to cut weeds, clods and other materialtherebetween.

Suction intake conduit 34 begins adjacent anvil 66 between augers 58 and60 and is securely attached to frame 52. The conduit 34 receives andremoves loosened material conveyed thereto by the rotating augers.

The stationary arcuate bar assembly 68, which includes divider 96 and asturdy arcuate bar 98, is mounted upright in suction intake conduit 34(FIGS. 4, 5) and divides the conduit substantially in half. The bar 98is welded to divider 96 and anvil 66 and provides a reinforcement forthe anvil. The arcuate bar 98 has a width slightly less than that of therim 95 of the rotor, so a pair of rotor cutting blades passes on eachside of the arcuate bar assembly 68.

The arcuate bar assembly 78 serves a number of purposes. It cooperateswith rotor 64 to cut and shred material therebetween, and when oversizerocks enter the suction intake conduit 34 the rotating blades hurl themoutward, away from the conduit. The arcuate bar assembly with itsdivider 96 prevents rocks from lodging between the rotating blades ofthe rotor and supports the suction intake conduit, giving it additionalstrength and rigidity while dividing the conduit substantially in halfto regulate the maximum size of material which can enter the conduit 34.The arcuate bar 98 is spaced from and confronts the rim 95 of rotor 64and provides a support against which rotor 64 can bear when shaft 54 isflexed rearwardly toward arcuate bar 98 as, for example, might occurwhen the shaft and augers encounter a major obstruction on the marshbottom; the bar thus insures that the shaft 54 retains a predeterminedrelationship with the suction intake conduit 34 in which the shaftcannot be seriously deformed.

In operation, when a marsh bottom is to be dredged to remove weeds,silt, mud, and like material the cable 22 is extended through the dredge10 and anchored on shore and at a distance out in the marsh. The dredge10 is winched along the cable 22 to a convenient starting location inthe marsh, nd the boom 16 is lowered to position the head 20 at adesired dredging depth. If the dredge is to be moved forwardly, the mudshield 46 is moved to a position similar to that shown in FIG. 2.

The dredge moves forward with shaft 54 rotating, and the cutting bladesof screw augers 58 and 60 dig into the marsh bottom, loosening material.Weeds and mud clods are cut and broken between the blades and toothedcutter bars 74 and 76 (FIG. 3). Material which is hurled upwardly andaway by the spinning augers is intercepted to a considerable degree bymud shield 46 and confined near the augers.

The rotating augers convey the confined loosened material to the intakeassembly 62 where the material encounters rotor 64 with its cuttingblades as the material leaves the augers. The rotor and its bladescooperate with stationary anvil 66 and arcuate bar assembly 68 tofurther cut and shred the loosened material and break up any remainingclods before they enter the suction intake conduit. Rocks conveyed tothe conduit 34 which are large enough to clog the conduit are hurledaway by the blades of the rotor 64.

If the rotor, shaft, or augers strike major obstructions on the marshbottom which force the shaft rearwardly, arcuate bar assembly 68supports the rotor and shaft thereby preventing any serious deformationof the shaft.

Spinning rotor 64 maintains the loosened material reaching intakeassembly 62 in suspension to aid suction intake conduit 34 in removingthe material. The dredge pump 32 draws the material upward throughflexible hose 36 and into rock collection box 38. Most rocks enteringthe intake conduit 34 are collected in box 38 and an operatorperiodically removes them. The remaining dredged material enters dredgepump 32 and is expelled at pump outlet 42 into a series of hoses whichtransport the material away from the dredging area.

When the dredge reaches the end of a swath, the shore anchor point ismoved to one side to permit the dredge to move rearwardly on a newcutting swath adjacent to the first. As the rearward swath is begun, anoperator adjusts the position of mud shield 46 by activating hydraulicpiston 48 to rotate mud shield 46 to a position like that shown inFIG. 1. The dredge is now ready for rearward operation. Since rearwardoperation of the dredging head is otherwise similar to forwardoperation, the rearward operation will not be described in furtherdetail.

While I have described a preferred embodiment of the present invention,it should be understood that various changes, adaptations andmodifications may be made therein without departing. from the spirit ofthe invention and the scope of the appended claims.

I claim:

l. A head to be carried by a boom of a forward and rearward moving,pumping dredge to loosen and remove material from the bottom of a bodyof water comprising:

an elongate frame attached to the boom and extend ing transversely ofthe boom;

a suction intake conduit attached to the frame and supplying material tothe dredge pump;

a shaft rotatably mounted to the frame, and drive means revolving theshaft;

a pair of spaced digging and conveying screw augers mounted on the shaftand extending horizontally and transversely of the forward direction andoutwardly from the suction intake conduit, the augers loosening andconveying material toward the suction intake conduit as the dredge headmoves along the bottom;

an elongate plate-like bar mounted on the elongate frame and extendingalong the length of said augers, the bar being oriented in a generallyupright position above the augers and in closely spaced relationthereto; and

an adjustable elongate panel of sturdy material pivotally mounted on theelongate frame and above said plate-like bar and extending along saidelongate frame and plate-like bar, said panel being concavely shapedwith the concave side facing and overlying the screw augers to conformto the general direction of flow of material created by the augers, saidpanel being disposed forwardly of the suction intake conduit andplate-like bar to cooperate with the bar in confining loosened materialnear the augers so the augers can convey the loosened material to thesuction intake conduit for removal.

2. The combination according to claim 1 wherein the panel extendsforwardly of the augers and the augers rotate with the lowermost edgesof the augers moving forwardly to loosen material, the material beingconfined by panel, augers, and water bottom, and the suction intakeconduit removing the confined material.

3. The combination according to claim 1 and including a plurality ofcutting blades on the augers and revolving therewith, said barsincluding teeth cooperating with the revolving blades of said screwaugers.

4. The combination according to claim 1 including means to vary theangular position of the panel.

5. A dredging head intake assembly for removing material loosened fromthe bottom of a body of water by a pair of augers spaced from oneanother on a shaft which is rotatably mounted to a frame comprising:

a rotor mounted on the shaft between the augers for rotating movementtherewith, said rotor carrying a plurality of cutting blades;

a stationary anvil attached to the frame and arranged to cooperate withthe rotor and blades to cut material therebetween;

a suction intake conduit adjacent the anvil and between the pair ofaugers to receive and remove loosened material; and

a stationary arcuate bar assembly maintaining the shaft and intakeconduit in a predetermined relation with one another, said bar assemblyattached to the conduit and frame reinforcing and dividing the conduit.

6. The combination according to claim 5 wherein said arcuate barassembly is spaced from the rotor and arranged to support the rotor whenthe shaft is flexed against the bar assembly.

7. The combination according to claim 5 wherein the arcuate bar assemblycontacts said anvil to provide a reinforcement for the anvil.

8. The combination according to claim 5 wherein the arcuate bar assemblyincludes an arcuate bar and a divider, the divider supporting thearcuate bar and attached to the conduit and frame.

9. The combination according to claim 5 wherein:

said rotor is disk shaped with flat sides separated by a circular rim,each side carrying at least one cutting blade; and

said arcuate bar assembly has a width less than the width of the rotorand confronts the rim of the rotor so that atleast one cutting bladepasses on each side of the arcuate bar assembly when the shaft rotates,the bar assembly cooperating with the rotor and blades to cut material.

10. The combination according to claim 5 wherein a panel of sturdymaterial is mounted overlying the augers to confine loosened materialnear the augers so material can be conveyed to the suction intakeconduit by the augers and removed.

11. The combination according to claim 10 wherein said panel ispivotally mounted for movement about an axis substantially parallel tothe head so the panel can overlie the head in a plurality of angularpositions.

1. A head to be carried by a boom of a forward and rearward moving,pumping dredge to loosen and remove material from the bottom of a bodyof water comprising: an elongate frame attached to the boom andextending transversely of the boom; a suction intake conduit attached tothe frame and supplying material to the dredge pump; a shaft rotatablymounted to the frame, and drive means revolving the shaft; a pair ofspaced digging and conveying screw augers mounted on the shaft andextending horizontally and transversely of the forward direction andoutwardly from the suction intake conduit, the augers loosening andconveying material toward the suction intake conduit as the dredge headmoves along the bottom; an elongate plate-like bar mounted on theelongate frame and extending along the length of said augers, the barbeing oriented in a generally upright position above the augers and inclosely spaced relation thereto; and an adjustable elongate panel ofsturdy material pivotally mounted on the elongate frame and above saidplate-like bar and extending along said elongate frame and plate-likebar, said panel being concavely shaped with the concave side facing andoverlying the screw augers to conform to the general direction of flowof material created by the augers, said panel being disposed forwardlyof the suction intake conduit and plate-like bar to cooperate with thebar in confining loosened material near the augers so the augers canconvey the loosened material to the suction intake conduit for removal.2. The combination according to claim 1 wherein the panel extendsforwardly of the augers and the augers rotate with the lowermost edgesof the augers moving forwardly to loosen material, the material beingconfined by panel, augers, and water bottom, and the suction intakeconduit removing the confined material.
 3. The combination according toclaim 1 and including a plurality of cutting blades on the augers andrevolving therewith, said bars including teeth cooperating with therevolving blades of said screw augers.
 4. The combination according toclaim 1 including means to vary the angular position of the panel.
 5. Adredging head intake assembly for removing material loosened from thebottom of a body of water by a pair of augers spaced from one another ona shaft which is rotatably mounted to a frame comprising: a rotormounted on the shaft between the augers for rotating movement therewith,said rotor carrying a plurality of cutting blades; a stationary anvilattached to the frame and arranged to cooperate with the rotor andblades to cut material therebetween; a suction intake conduit adjacentthe anvil and between the pair of augers to receive and remove loosenedmaterial; and a stationary arcuate bar assembly maintaining the shaftand intake conduit in a predetermined relation with one another, saidbar assembly attached to the conduit and frame reinforcing and dividingthe conduit.
 6. The combination according to claim 5 wherein saidarcuate bar assembly is spaced from the rotor and arranged to supportthe rotor when the shaft is flexed against the bar assembly.
 7. Thecombination according to claim 5 wherein the arcuate bar assemblycontacts said anvil to provide a reinforcement for the anvil.
 8. Thecombination according to claim 5 wherein the arcuate bar assemblyincludes an arcuate bar and a divider, the divider supporting thearcuate bar and attached to the conduit and frame.
 9. The combinationaccording to claim 5 wherein: said rotor is disk shaped with flat sidesseparated by a circular rim, each side carrying at least one cuttingblade; and said arcuate bar assembly has a width less than the width ofthe rotor and confronts the rim of the rotor so that at least onecutting blade passes on each side of the arcuate bar assembly when theshaft rotates, the bar assembly cooperating with the rotor and blades tocut material.
 10. The combination according to claim 5 wherein a panelof sturdy material is mounted overlying the augers to confine loosenedmaterial near the augers so material can be conveyed to the suctionintake conduit by the augers and removed.
 11. The combination accordingto claim 10 wherein said panel is pivotally mounted for movement aboutan axis substantially parallel to the head so the panel can overlie thehead in a plurality of angular positions.